51961323856 has 40 divisors (see below), whose sum is σ = 108987024384. Its totient is φ = 23856570240.

The previous prime is 51961323809. The next prime is 51961323907. The reversal of 51961323856 is 65832316915.

It is a happy number.

It is a super-2 number, since 2×51961323856² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 614236 + ... + 693691.

Almost surely, 2^51961323856 is an apocalyptic number.

It is an amenable number.

51961323856 is an abundant number, since it is smaller than the sum of its proper divisors (57025700528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51961323856 is a wasteful number, since it uses less digits than its factorization.

51961323856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1308139 (or 1308133 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 49.

The spelling of 51961323856 in words is "fifty-one billion, nine hundred sixty-one million, three hundred twenty-three thousand, eight hundred fifty-six".